Electronic structure of noble-metal monoxides: PdO, PtO, and AgO

Electronic structure of mixed-valence silver oxide AgO from hybrid density-functional theory

“…12 This oxygen-hole theory was postulated due to the small O p-Ag d energy separation. 12 X-ray photoelectron spectroscopy ͑XPS͒ studies of AgO have reported two O 1s core levels despite the fact that only one inequivalent oxygen site exists in the structure. 10 The presence of these two core levels is attributed to oxygen in −2 and −1 valences, 10 consistent with the theory of Park et al 12 Another study of AgO using XPS and electron energyloss spectroscopy cast doubt on the presence of Ag III in AgO.…”

“…12 X-ray photoelectron spectroscopy ͑XPS͒ studies of AgO have reported two O 1s core levels despite the fact that only one inequivalent oxygen site exists in the structure. 10 The presence of these two core levels is attributed to oxygen in −2 and −1 valences, 10 consistent with the theory of Park et al 12 Another study of AgO using XPS and electron energyloss spectroscopy cast doubt on the presence of Ag III in AgO. They stated that it was difficult to understand how Ag III forms due to the fact that no other Ag compound with the Ag III valence had been reported, 11 despite the fact that the crystal structure of Ag 2 O 3 had been reported five years earlier.…”

“…15 Early theoretical calculations carried out using localdensity approximation ͑LDA͒ within the full-potential linearized augmented-plane-wave method have challenged the view that Ag I and Ag III are present in AgO. 12 The authors predicted that the cation valences are Ag I and Ag II with holes present on the oxygen ions. 12 This oxygen-hole theory was postulated due to the small O p-Ag d energy separation.…”

“…12 The authors predicted that the cation valences are Ag I and Ag II with holes present on the oxygen ions. 12 This oxygen-hole theory was postulated due to the small O p-Ag d energy separation. 12 X-ray photoelectron spectroscopy ͑XPS͒ studies of AgO have reported two O 1s core levels despite the fact that only one inequivalent oxygen site exists in the structure.…”

“…6 Although not as widely studied as Ag 2 O, several structural and spectroscopic studies have been carried out on AgO in an effort to elucidate the geometry and electronic structure of the material. [7][8][9][10][11][12] AgO crystallizes in a monoclinic structure ͑space group P12 1 / c1͒ with Ag ions in two distinct coordination environments. 7 Neutron-diffraction experiments have indicated that it is composed of linearly coordinated Ag ions ͑denoted Ag lin ͒ and Ag ions in a slightly distorted square planar coordination with four oxygens 8 ͑denoted Ag sq ͒, as shown in Fig.…”